1. Field of the Invention
This invention relates to a color television camera system, and more particularly to a color television camera system wherein red (R) and blue (B) color signals are line-sequentially obtained from a pickup device.
2. Description of the Prior Art
There have been proposed many types of color television camera systems. Among them, it has been proposed to use a color filter which has red color and blue color elements alternately aligned in the vertical direction. In case of this system, two pick up devices are employed for establishing the entire color television camera system. One of two pick up devices carries the above mentioned red and blue color filters and the other carries a green (G) color filter. In a first approach, a luminance signal is originated by mixing a single line signal of the green pick up device and two lines, namely red and blue lines, of signals of the red-blue pick up device. In such a case, low frequency components of this synthesized luminance signal may include undesired signal components depending on a color condition of the object. The undesired signals are likely to be generated in the luminance signal when blue or red color of the object is gradually changing in the vertical direction of television scanning. FIG. 1A shows color components of an object, wherein red and blue color components are oppositely changed in the vertical direction. If the output of the pick up device is smooth such as shown in FIG. 1A, the synthesized luminance signal may also be smooth as shown in FIG. 2A. But actually, the output of the pick up device has a sampled signal formed by color filter elements. Also, sample timings of blue and red color filter elements are out of phase with each other in the vertical direction. Therefore, changes of red and blue color components from the pick up device show waveforms depicted in FIG. 1B. Accordingly, the synthesized luminance signal of the prior art may include undesired components such as shown in FIG. 2B. These will cause a dot-like pattern in the vertical direction of the reproduced color picture.